Comparison of Subcellular Partitioning, Distribution, and Internal Speciation of Cu between Cu-Tolerant and Naïve Populations of Dendrodrilus rubidus Savigny

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• 作者：Becky E. Arnold ; Mark E. Hodson ; John Charnock ; Willie J.G.M. Peijnenburg
• 刊名：Environmental Science & Technology
• 出版年：2008
• 出版时间：May 15, 2008
• 年：2008
• 卷：42
• 期：10
• 页码：3900 - 3905
• 全文大小：277K
• 年卷期：v.42,no.10(May 15, 2008)
• ISSN：1520-5851

文摘

When considering contaminated site ecology and ecological risk assessment a key question is whether organisms that appear unaffected by accumulation of contaminants are tolerant or resistant to those contaminants. A population of Dendrodrilus rubidus Savigny earthworms from the Coniston Copper Mines, an area of former Cu mining, exhibit increased tolerance and accumulation of Cu relative to a nearby non-Cu exposed population. Distribution of total Cu between different body parts (posterior, anterior, body wall) of the two populations was determined after a 14 day exposure to 250 mg Cu kg⁻¹ in Cu-amended soil. Cu concentrations were greater in Coniston earthworms but relative proportions of Cu in different body parts were the same between populations. Cu speciation was determined using extended X-ray absorption fine structure spectroscopy (EXAFS). Cu was coordinated to O atoms in the exposure soil but to S atoms in the earthworms. There was no difference in this speciation between the different earthworm populations. In another experiment, earthworms were exposed to a range of Cu concentrations (200−700 mg Cu kg⁻¹). Subcellular partitioning of accumulated Cu was determined. Coniston earthworms accumulated more Cu but relative proportions of Cu in the different fractions (cytosol > granular > tissue fragments, cell membranes, and intact cells) were the same between populations. Results suggest that Coniston D. rubidus are able to survive in the Cu-rich Coniston Copper Mines soil through enlargement of the same Cu storage reservoirs that exist in a nearby non-Cu exposed population.